This application is based upon and claims the benefit of Japanese Patent Applications No. 11-321632 filed on Nov. 11, 1999, No. 2000-193147 filed on Jun. 27, 2000, and No. 2000-275306 filed on Sep. 11, 2000, the contents of which are incorporated herein by reference.
1. Field of the Invention
This invention relates to an air passage opening/closing device for opening and closing an air passage by moving a film member in the air passage. The device is suitable for use for example in a vehicle air conditioner.
2. Description of the Related Art
An air passage opening/closing device for switching an air passage by movement of a film member is proposed in JP-A-8-2238. In this related art, the ends of a flexible film member such as a resin film are attached to a driving shaft and a following shaft rotatably mounted in an air-conditioning case, a pulley is connected coaxially to an end of each of the shafts, and the ends of a wire are wound on the pulleys. The driving shaft is connected to a motor and is rotationally driven by the motor.
When the driving shaft is rotated in the direction in which it takes up (winds) the film member, the driving shaft directly takes up (winds) the film member and thus moves the film member inside the air-conditioning case. When reversely the driving shaft is rotated in the direction in which it lets out (rewinds) the film member, this rotation of the driving shaft is transmitted via the pulleys and the wire to the following shaft. Therefore, the following shaft rotates in the direction in which it takes up (winds) the film member, and the film member is wound around the following shaft and thus moved inside the air-conditioning case in the opposite direction. By the film member being moved in forward and reverse directions inside the air-conditioning case, an air passage can be opened and closed.
However, in this related art, because the ends of the film member are respectively connected to and are wound by the driving shaft and the following shaft, it is necessary for the driving shaft and the following shaft to be operatively coupled. Consequently, an operatively coupling mechanism such as pulleys and a wire is necessary. Therefore, the number of parts in the device becomes large, its assembly is complicated, and its cost is high.
It is therefore an object of the invention to provide an air passage opening/closing device for opening and closing an air passage using a flexible film member, which has a simple structure without a winding mechanism of the film member.
According to the present invention, in an air passage opening/closing device, a film member having a predetermined flexible performance is disposed to be reciprocated in an air passage for opening and closing the air passage, a driving member is disposed to apply driving force for a reciprocating movement of the film member to at least one position of the film member, and a guide member is disposed to guide the film member for the reciprocating movement of the film member. The film member has a rigidity equal to or larger than a predetermined degree, so that the film member moves along the guide member when a pushing force pushing the film member is applied to the film member from the driving member. Thus, when the driving force is applied to the film member from the driving member, the film member reciprocates along the guide member. Accordingly, the air passage opening/closing device using the film member has a simple structure without using a winding mechanism of the film member.
Preferably, the driving member includes a driving shaft and a driving gear driven by the driving shaft, the film member is reciprocated by the rotation of the driving gear, and a pressing member is disposed in the air duct to press the film member onto the driving gear. Therefore, the engagement between the driving gear and the film member can be accurately maintained using the pressing member.
Preferably, at least one end of the film member in a reciprocating direction has a supported part supported by the guide member, and a non-supported part except for the supported part. Further, the non-supported part is recessed from the supported part. Thus, the end of the film member in the reciprocating direction can be accurately readily received in a receiving space of an air duct while being smoothly guided by the guide member.
According to the present invention, the film member has at least a fee end in the reciprocating direction of the film member, the air passage has a plurality of openings opened in the air duct toward a direction perpendicular to the reciprocating direction, the openings are partitioned by a partition portion of the air duct between the openings, and the driving member is disposed at a position on an extending line of the partition portion. Thus, an additional space for only the driving member is unnecessary. Accordingly, the size of the air passage opening/closing device can be made smaller, and it is possible to increase the opening area of the openings.
Alternatively, in a case where at least one of the openings is an always opened port by the film member, the driving member can be disposed at a position on an extending line of the always opened port. Even in this case, an additional space for only the driving member is unnecessary.
Preferably, the driving member is a driving sprocket having teeth, the film member has engagement holes engaging with the teeth of the driving sprocket, and the engagement holes are arranged on the extending line. Therefore, the reciprocating operation of the film member can be made simple.
Preferably, the air duct has a peripheral member defining an opening communicating the air passage, the film member has a film stopper member at an end in the reciprocating direction, the peripheral member has an peripheral stopper member protruding to the opening of the air passage, and the peripheral stopper member engages with the film stopper member at a predetermined movement position of the film member. Therefore, the film member is reciprocated accurately in a predetermined movement range.